The most senior Christian cleric in Iraq said the United States was "indirectly responsible" for the current chaos in Iraq, where the advances of Islamic State jihadists over the past few months have led to thousands of deaths and raised charges of ethnic cleansing. In August alone, some 600,000 people were displaced by the violence.

"[The U.S.] said it would ensure democracy and the well-being of the people. But 10 years have passed, and, on the contrary, we have gone backward," said Chaldean Catholic Patriarch Louis Sako, during a visit to Beirut last week. He added: "There were about 1 million Christians in Iraq and more than half of them have been displaced. Only 400,000 are left while displacement is still rising."

Sako's denomination is one of the world's most ancient Christian communities. Most are ethnic Assyrians, a group that existed for centuries in what's now modern-day Iraq, Syria and Turkey and preserved their faith and language -- a version of Aramaic -- through the various upheavals and conquests that have shaped and reshaped the Middle East.

But their place within the Iraqi state changed radically after the U.S. invasion in 2003. After the toppling of Saddam Hussein, a nominally secular dictator, there was a security vacuum that imperiled Iraq's religious minorities. The new government in Baghdad, dominated by Shiites long repressed by Hussein's regime, failed to build a truly inclusive democracy. Tens of thousands of Chaldeans left the country following attacks on churches and monasteries.

In 2008, Sako's predecessor, Mar Emmanuel III Delly, was very clear about what was to blame for his congregation's troubles. "The absolute worst time that I've seen in my life has been the last five years, " he told the Detroit Free Press (there's a considerable Assyrian diaspora in Michigan). "The occupation has not been good for the Christians and for all of Iraq."

Sako has been outspoken about the horrors visited upon Iraq this summer by the Islamic State, whose puritanical brand of Islam has driven it to systematically butcher Christians, Yazidis and others belonging to Iraq's mosaic of minority sects. The jihadists have set about destroying cultural monuments -- tombs and shrines -- that it considers the work of apostates.

After the loss of the historic city of Mosul to the Islamic State fighters, Sako offered an apocalyptic lament during a July sermon in Bagdhad, which WorldViews covered:

"How in the 21st century could people be forced from their houses just because they are Christian, or Shi'ite or Sunni or Yazidi?" he asked. "Christian families have been expelled from their houses and their valuables were stolen and ...their houses and property expropriated in the name of the Islamic State."

[Sako] went on to make a chilling, grand historic proclamation: "This has never happened in Christian or Islamic history. Even Genghis Khan or Hulagu didn't do this," he said. Hulagu Khan was the Mongol warlord whose horde swept through Mosul en route to sacking Baghdad in 1258, a bloody slaughter that snuffed out the proud Abbasid caliphate that had flourished there since the 8th century. Baghdad would take hundreds of years to reemerge as a political center.

Some 200 Muslims also attended that particular service, according to Reuters, and held up signs in solidarity reading "I am Iraqi, I am Christian." But that support belies the larger alienation that Sako says his flock has endured, even as the United States and other allies step up aerial strikes on Islamic State positions in Iraq.

"Our Muslim neighbors did not help us," he told reporters last month. "The West watched us, and it seemed they have ignored our suffering. But we will not leave our land, whatever the sacrifices."